GEOMETRIC PROPERTIES OF GENERALIZED DINI FUNCTIONS

Deniz, Erhan,Goren, Seyma The Honam Mathematical Society 2019 호남수학학술지 Vol.41 No.1

In this paper our aim is to establish some geometric properties (like starlikeness, convexity and close-to-convexity) for the generalized and normalized Dini functions. In order to prove our main results, we use some inequalities for ratio of these functions in normalized form and classical result of Fejer.

Individual and combined effect of Portland cement and chemical agents on unconfined compressive strength for high plasticity clayey soils

Yilmaz, Yuksel,Eun, Jongwan,Goren, Aysegul Techno-Press 2018 Geomechanics & engineering Vol.16 No.4

Unconfined compressive strength (UCS) of high plasticity clayey soil mixed with 5 and 10 % of Portland cement and four chemical agents such as sodium hexametaphosphate, aluminum sulfate, sodium carbonate, and sodium silicate with 0, 5, 10, and 20% concentrations was comparatively evaluated. The individual and combined effects of the cement and chemical agents on the UCS of the soil mixture were investigated. The strength of the soil-cement mixture generally increases with increasing the cement content. However, if the chemical agent is added to the mixture, the strength of the cement-chemical agent-soil mixture tends to vary depending on the type and the amount of the chemical agent. At low concentrations of 5% of aluminum sulfate and 5% and 10% of sodium carbonate, the average UCS of the cement-chemical agent-soil mixture slightly increased compared to pure clay due to increasing the flocculation of the clay in the mixture. However, at high concentrations (20%) of all chemical agents, the UCS significantly decreased compared to the pure clay and clay-cement mixtures. In the case of high cement content, the rate of UCS reduction is the highest among all cement-chemical agent-soil mixtures, which is more than three times higher in comparison to the soil-chemical agent mixtures without cement. Therefore, in the mixture with high cement (> 10%), the reduction of the USC is very sensitive when the chemical agent is added.

기업지배구조의 변화가 주주의 부에 미치는 영향

조광현,안희영,Rifat Gorener,최성호 한국산업경제학회 2010 산업경제연구 Vol.23 No.6

이 논문은 국내 상장기업을 대상으로 기업지배구조 등급의 변화가 주주의 부에 미치는 영향을 사건 연구 방법을 통해 실증분석하였다. 본 연구의 주요결과를 요약하면 다음과 같다. 첫째, 사건연구를 통한 분석결과 지배구조 등급변경의 공시 사건일(event window)에 측정한 누적평균초과수익률(CAAR)은 통계적으로 유의한 수준에서 음(-)의 값으로 나타났다. 이는 지배구조등급의 변화가 일반적으로 시장참여자들에게 해당기업에 대한 위험요인으로 받아들여지고 있음을 나타낸다. 둘째, 기업지배구조 등급의 변경을 상향조정과 하향조정으로 구분하여 CAAR을 검증한 결과, 등급의 하향조정시 CAAR은 통계적으로 유의한 수준에서 음(-)의 값이 나타났다. 셋째, 기업지배구조의 등급 변화가 취약등급에서 보통이상의 등급으로 상향조정된 경우 CAAR 값은 양(+)의 값이 나타났고, 보통 이상의 등급에서 취약등급으로 하향 조정된 경우에는 CAAR 값들은 통계적으로 더욱 유의하게 음(-)의 값이 나타났다. 이 결과들은 기업지배구조의 변화가 시장에 적절히 반영되고 있음을 의미하며, 지배구조등급의 개선이 주주의 부를 높이고 지배구조등급의 악화가 주주의 부를 감소시킬 수 있음을 나타낸다. 넷째, 기업특성을 통제한 후 지배구조 등급의 변화와 초과수익률(CAR)간의 관계를 살펴본 회귀분석의 결과에서도 전체 표본을 이용하였을 때 등급의 상향 변경이 초과수익률과 유의한 양(+)의 상관관계를 가지는 것으로 확인되어, 시장참여자들이 지배구조등급의 변화에 민감하게 반응함이 나타났다. 또한 지배구조등급이 취약등급에서 보통이상의 등급으로 상향조정되는 경우 CAR가 유의하게 상승하는 것으로 나타났으며 계수 값 또한 다른 등급의 조정변화보다 크게 나타났다. 이러한 결과는 취약등급을 기준으로 이루어진 지배구조등급의 상하향이 시장에서 더 큰 정보로 받아들여지고 있음을 의미한다. 본 논문의 결과를 종합해보면 지배구조가 좋은 기업일수록 기업의 가치가 높게 평가되고, 이 결과는 기존의 연구결과들과 일치한다. This paper examines the effect of the changes in the rating group of the company's governance index on the wealth of stockholders. Specifically, this paper investigates the announcement effect of governance index group changes which is measured by the cumulative abnormal returns to stockholders of rating group-changed company. The empirical results are as follows. First, the empirical test indicates that on average the cumulative abnormal return (CAAR) is significantly negative in various event windows. This finding implies that the announcement of governance rating group changes plays as an additional risk factor to stockholders, resulting in a lower return. However, changes in corporate governance ratings have different results depending on whether the rating change is upgrade on not. While the downgrade of governance rating results in a significantly negative abnormal returns to the stockholders, the CAAR is positive when there is an upgrade of governance rating. Further more, if the governance rating falls to the weakest group, the cumulative abnormal return is significantly negative. On the other hand, the upgrade from the weakest group results in a significantly positive CAR to the stockholders. Finally, after controlling the firm specific characteristics, the regression analysis confirms our previous results. These results are consistent with the literature that the good governance practice increases the value of firm.

Can sunlight affect COVID-19 outcomes? What is the available evidence?

Mohammad Reza Khazdair,Andy Goren 대한응급의학회 2021 Clinical and Experimental Emergency Medicine Vol.8 No.3

Sunlight modulated the immune system by production of vitamin D. Furthermore, both influenza and SARS-CoV-2 are dependent on TMPRSS2 for infectivity, and sunlight can useful for SARS-CoV-2 by reducing androgen sensitivity and lowering expression of TMPRSS2.

Bypassing Negative Epistasis on Yield in Tomato Imposed by a Domestication Gene

Soyk, Sebastian,Lemmon, Zachary H.,Oved, Matan,Fisher, Josef,Liberatore, Katie L.,Park, Soon Ju,Goren, Anna,Jiang, Ke,Ramos, Alexis,van der Knaap, Esther,Van Eck, Joyce,Zamir, Dani,Eshed, Yuval,Lippma Cell Press 2017 Cell Vol. No.

<P><B>Summary</B></P> <P>Selection for inflorescence architecture with improved flower production and yield is common to many domesticated crops. However, tomato inflorescences resemble wild ancestors, and breeders avoided excessive branching because of low fertility. We found branched variants carry mutations in two related transcription factors that were selected independently. One founder mutation enlarged the leaf-like organs on fruits and was selected as fruit size increased during domestication. The other mutation eliminated the flower abscission zone, providing “jointless” fruit stems that reduced fruit dropping and facilitated mechanical harvesting. Stacking both beneficial traits caused undesirable branching and sterility due to epistasis, which breeders overcame with suppressors. However, this suppression restricted the opportunity for productivity gains from weak branching. Exploiting natural and engineered alleles for multiple family members, we achieved a continuum of inflorescence complexity that allowed breeding of higher-yielding hybrids. Characterizing and neutralizing similar cases of negative epistasis could improve productivity in many agricultural organisms.</P> <P><B>Video Abstract</B></P> <P>Display Omitted</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mutations in two MADS-box genes were selected in tomato domestication and breeding </LI> <LI> Interaction of the alleles caused extreme inflorescence branching and sterility </LI> <LI> Natural and gene-edited MADS-box alleles provide a range of inflorescence types </LI> <LI> Dosage from selected alleles allows improved inflorescence architecture and yield </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preventive Effect of Probiotics and α-Tocopherol on Ethanol-Induced Gastric Mucosal Injury in Rats

Altug Senol,Mehmet Isler,Aynur G. Karahan,Gulden B. Kilic,Hakan Kuleasan,Selcuk Kaya,Muharrem Keskin,Ibrahim Goren,Ulku Saritas,Buket C. Aridogan,Namik Delibas 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.1

The protective effect of a probiotic mixture of 13 different bacteria and α-tocopherol on 98% ethanol-induced gastric mucosal injury was evaluated. Levels of gastric mucosal pro- and anti-inflammatory cytokines, malondialdehyde, and secretory immunglobulin A were measured. Rats were allocated into four groups: control, ethanol, probiotic, and α-tocopherol. The control and ethanol groups received skim milk for 14 days. Probiotic and α-tocopherol groups were administered probiotic mixture suspended in skim milk and 100mg/kg α-tocopherol, respectively, by daily gavage for 14 days. On Day 15, gastric lesions were induced by administration of ethanol 98% (1mL) to all rats except those in the control group. Probiotic, but not α-tocopherol, seemed to inhibit ethanol-induced gastric mucosal tumor necrosis factor-α, interferon-γ, and interleukin-2 production (P>.05). Ethanol caused the elevation of mucosal interleukin-4 level (compared to the control, P<.05). Probiotic pretreatment significantly suppressed the ethanol-induced increase of gastric mucosal interleukin-4 levels. Pretreatment with either probiotic or α-tocopherol inhibited the ethanol-induced increase of mucosal malondialdehyde concentration (P<.01 and P<.05, respectively). Probiotic pretreatment enhanced the gastric mucosal secretory immunoglobulin A concentration (P<.001). In conclusion, probiotic mixture and α-tocopherol reduced ethanol-induced gastric mucosal lipid peroxidation, suggesting that they may be beneficial for gastric lesions induced by lower ethanol concentration.